The disclosure relates to the use of superabsorbent polymers for pressure control and diversion applications.
Hydraulic fracturing is a stimulation process for creating high-conductivity communication with a large area of a subterranean formation. The process increases the effective wellbore area within the formation so that entrapped oil or gas production can be accelerated. The efficiency of the process is often measured by the total amount of contacted surface area that results from the stimulation treatment.
During hydraulic fracturing, a fracturing fluid is pumped at pressures exceeding the fracture pressure of the targeted reservoir rock in order to create or enlarge fractures within the subterranean formation penetrated by the wellbore. Once the fracture is initiated, subsequent stages of fluid containing chemical agents, as well as proppants, are pumped into the created fracture. The fracture generally continues to grow during pumping and the proppants remain in the fracture in the form of a permeable pack that serves to prop the fracture open. Once the treatment is completed, the fracture closes onto the proppants. The proppants keep the created fracture open, providing a highly conductive pathway for hydrocarbons and/or other formation fluids to flow into the wellbore.
To increase the productivity of hydrocarbons, it is desirable to increase the fracture area and the fracture complexity. However, during a hydraulic fracturing operation, fracturing fluids tend to flow to fractures or high permeable zones, affecting the total fracture area and the fracture complexity. Accordingly it may be desirable to add a diverting agent toward the end of an operation treating a section of a subterranean formation such that the agent will then slow or stop the flow of further treatment fluid into that area, thus diverting later-injected fluid to other areas of interest. Despite all the advances in the art, there is a continuing need for an improved method of diverting fluids during hydraulic fracturing operations.
In addition, high permeability formations, fractures, or depleted reservoir can also have excessive fluid leakoff rates. Excessive fluid leakoff can lead to a loss of wellbore pressure, which can affect coiled tubing operations which relies on sufficient wellbore pressure to maintain circulation to the surface while performing ongoing treatments within the well. Accordingly, there is also a need for methods that are effective to reduce or eliminate fluid leakoff during a coiled tubing operation.